One sentence carries most of the federal weight. 29 CFR 1926.551(h) makes the helicopter operator responsible for the size, weight, and manner in which loads are connected to the aircraft, and gives that operator an unconditional veto over the lift. Of the eighteen lettered paragraphs in the rule, none names the general contractor.
The question surfaces at every preconstruction meeting where an aerial lift is on the schedule. A ground crane project answers it easily, because OSHA built a dense architecture of named roles for cranes in construction: a certified operator, a qualified signal person, an assembly and disassembly director, a controlling entity with specific written duties. Estimators and safety managers know those titles and know which line of the subcontract each one attaches to.
A helicopter lift has almost none of that architecture, and the reason is a single line of exclusion text. The whole federal role structure for an external-load job sits in eighteen lettered paragraphs of one OSHA construction standard and in 14 CFR Part 133. What those instruments assign is narrower than most project teams assume, and what they leave unassigned is wider. The gap is not a loophole. It is the space the contract is supposed to fill, and it is where disputes start when the contract does not.
The two sentences that carry most of the weight
Paragraph (h) of the helicopter standard is titled "Operator responsibility" and reads in full: "The helicopter operator shall be responsible for size, weight, and manner in which loads are connected to the helicopter. If, for any reason, the helicopter operator believes the lift cannot be made safely, the lift shall not be made."
Two things in that text are routinely misread. The first is who "the helicopter operator" is. It is the aviation company flying the job, not the party that owns the load, fabricated it, or weighed it. A contractor who supplies a bad weight has breached a contract and may well have created a hazardous condition, but the regulatory responsibility for accepting that weight onto the hook sits with the aviation operator. The second is the phrase "for any reason." The veto in the second sentence has no standard of proof attached to it, no appeal, and no requirement that the reason be aeronautical. Belief is the entire test.
Alongside it sits the oldest allocation in American aviation law. 14 CFR 91.3(a) states that the pilot in command "is directly responsible for, and is the final authority as to, the operation of that aircraft," and 14 CFR 91.7(b) makes that same pilot responsible for determining whether the aircraft is in condition for safe flight and requires the flight to be discontinued if it is not. Between the OSHA veto and the Part 91 authority, no project schedule, no owner directive, and no contract clause can compel a pick.
OSHA 1926.551 Ground crew rule
The crane rulebook does not apply, and that catches teams out
OSHA Subpart CC, Cranes and Derricks in Construction, opens at 29 CFR 1926.1400(a) by covering "power-operated equipment, when used in construction, that can hoist, lower and horizontally move a suspended load." A helicopter on a longline meets that description precisely. Paragraph (c) then lists eighteen exclusions, and item (16) is two words long: "Helicopter cranes."
Everything downstream of that exclusion falls away. There is no third-party operator certification requirement, no documented signal person qualification, no assembly and disassembly director, and no controlling-entity duty to prepare ground or disclose subsurface hazards, because those obligations live in sections of Subpart CC that a helicopter lift never enters. The replacement is 29 CFR 1926.551 plus the Federal Aviation Regulations, and the substitution is not one for one.
29 CFR 1926.1400 Crane rule exclusions
| Function | On a ground crane job | On a helicopter lift |
|---|---|---|
| Operator qualification | Third-party certification or licensing plus employer evaluation, 1926.1427(a) | FAA commercial or airline transport pilot certificate, plus a letter of competency or logbook entry carried in personal possession, 14 CFR 133.37(a)(2) |
| Signal person qualification | Documented third-party or employer qualified evaluator, oral or written test plus practical test, documentation kept on site, 1926.1428 | None. One "designated employee of the ground crew" who is "distinctly recognizable from other ground personnel," 1926.551(r) |
| Rigging and assembly supervision | An A/D director who is both a competent and a qualified person, 1926.1404(a) | No equivalent role exists in the rule |
| Ground conditions and subsurface hazards | The controlling entity must ensure ground preparation and disclose known voids, tanks and utilities, 1926.1402(c) | No equivalent. Nothing bears on the ground, so the duty has no subject |
| Coordinating overlapping machines | The controlling entity must institute a coordination system, 1926.1424(b) | No equivalent in the rule |
| Daily pre-work briefing | Not a general Subpart CC requirement | Mandatory before each day's operation, setting out the plan for pilot and ground personnel, 1926.551(b) |
| Load rating ceiling | Manufacturer load chart under the operational requirements of 1926.1417 | Manufacturer's rating, 1926.551(k), and the type-certificated weight and centre of gravity envelope, 14 CFR 133.43(c) |
| Hook and release hardware check | Shift inspection under 1926.1412(d) | Cargo hook release tested electrically and mechanically prior to each day's operation, 1926.551(d) |
Comparison built from the current text of 29 CFR 1926.551, Subpart CC, and 14 CFR Part 133. The helicopter column is thinner in personnel qualification and thicker in daily verification, which is the opposite of the pattern most construction safety programs are written around.
The signalperson is one designated employee, and the rule stops there
Paragraph (r) of the helicopter standard reads: "There shall be constant reliable communication between the pilot, and a designated employee of the ground crew who acts as a signalman during the period of loading and unloading. This signalman shall be distinctly recognizable from other ground personnel." Paragraph (n) adds that the signal system, radio or hand, "shall be understood and checked in advance of hoisting the load," and points hand signals to Figure N-1 of the standard.
That is the complete federal specification. There is no test, no evaluator, no documentation kept at the site, and no rule against an assessment travelling between employers. A crane signal person on the same project must satisfy five enumerated qualification criteria under 1926.1428(c) and hold paperwork proving it. The helicopter signalperson must be designated, must be visually distinct, and must be in constant reliable contact with the pilot.
The unresolved word is "employee." The rule says a designated employee of the ground crew without saying whose payroll that person is on. In practice the aviation operator often supplies its own ground personnel for exactly this reason, and where the contractor designates the signalperson instead, the designation needs to be written down before the aircraft launches rather than settled on the pad. The same silence runs through the hookup crew under paragraphs (i) and (j), the people who go under a hovering aircraft to engage and disengage slings. What those crews wear is specified in detail, as set out in the AHLH treatment of ground crew PPE requirements. Who employs them is not.
What the certificate holder owns, and cannot hand over
Part 133 loads a stack of obligations onto the Rotorcraft External-Load Operator Certificate holder that no contract can move. 14 CFR 133.21(b) requires the operator to designate a chief pilot acceptable to the Administrator, and paragraph (c) of the same section requires any change in that designation to be reported immediately to the responsible Flight Standards office, with a new chief pilot in place within 30 days or operations under the certificate stop.
14 CFR 133.47 requires the operator to prepare a Rotorcraft-Load Combination Flight Manual and submit it for FAA approval, and 14 CFR 133.33(a) closes the loop: "No person may conduct a rotorcraft external-load operation without, or contrary to, the Rotorcraft-Load Combination Flight Manual." 14 CFR 133.45 then requires the operator to establish the operating limitations for the combination and write them into that manual. Verifying that this paperwork exists and matches the aircraft actually showing up is a client-side diligence task, covered in the AHLH guidance on vetting a lift operator and in the reference on what Part 133 certification means.
14 CFR 133.33 Operating rules 14 CFR 133.45 Operating limitations
Over a congested area, one duty is formally handed to a third party
14 CFR 133.33(d)(1) is the only place in the framework where a responsibility is moved out of the aviation operator and onto a party with no contract on the job. The operator "must develop a plan for each complete operation, coordinate this plan with the responsible Flight Standards office for the area in which the operation will be conducted, and obtain approval for the operation from that office." The plan "must include an agreement with the appropriate political subdivision that local officials will exclude unauthorized persons from the area in which the operation will be conducted."
FAA Advisory Circular 133-1B, dated 31 May 2017, publishes the model wording that the local official signs. It reads: "Personnel of the [name of the political subdivision] agree to exclude all unauthorized persons from the operational area described on the attached CAP, which was prepared for rotorcraft external-load operations. I understand that the operations will be conducted on [dates] and remove the operator's responsibility to exclude all unauthorized persons from the operational area." That final clause is an explicit transfer, in writing, of a duty the operator would otherwise carry alone.
14 CFR 133.33 Congested area plan
The sample plan form in the same advisory circular shows how far the paperwork reaches past the flight crew. It asks for the name, address and telephone number of the contractor as well as the operator, the name and title of the local official who agreed to exclude the public, the list of streets that will be blocked, the buildings that must be partially or entirely unoccupied along with their owners and telephone numbers, and the number of floors the load could penetrate if it were dropped from the highest point of lift above the building. Building owners are not signatories to the aviation contract, yet the plan cannot be assembled without them. The mechanics of that filing are set out in the AHLH work on congested area plans for urban lifts, and the parallel municipal approvals are mapped in the guide to lift permitting by jurisdiction.
Where OSHA stops and the FAA starts
Section 4(b)(1) of the Occupational Safety and Health Act withdraws OSHA standards from working conditions where another federal agency has exercised statutory authority over them. In 1975 the FAA did exactly that for flight crews. Its policy statement at 40 FR 29114 concluded that FAA authority "completely encompass[ed] the safety and health aspects of the work environments of aircraft crew members" and that the overall FAA regulatory program "fully occupies and exhausts the field of aircraft crew member occupational safety and health."
The boundary is temporal as well as physical. As OSHA describes it, an aircraft is in operation "from the time the aircraft is first boarded by a crew member, preparatory to a flight, to the time the last crewmember leaves the aircraft after the completion of that flight, including stops on the ground during which at least one crewmember remains on the aircraft, even if the engines are shut down." A 2013 FAA policy statement narrowed the preemption for cabin crewmembers on noise, hazard communication and bloodborne pathogens. It did not touch external-load flight crews.
The practical result is a seam that runs through the middle of the job. The aircraft, its crew, and the conduct of the flight answer to the FAA. The pad, the receiving crew, the rigging handled on the ground, the exclusion zone and the housekeeping answer to OSHA. Paragraph (h) reaches across that seam and hands the connection of the load to the aviation side, which is why a lift plan drafted entirely from a construction safety template tends to leave the middle of the sequence unowned. The sequencing of that handover is worked through in the AHLH reference on how a helicopter lift is planned.
14 CFR 91.3 Pilot in command authority
The roles matrix
The table below reads each role against the instrument that creates it, and marks whether the duty can be moved by agreement. The pattern is consistent: aviation duties are fixed to the certificate and the pilot, ground duties float to whichever employer the facts attach them to, and commercial duties are wherever the contract puts them.
| Role | Core duty | Where the duty comes from | Movable by contract? |
|---|---|---|---|
| Pilot in command | Final authority over the operation of the aircraft; determines it is fit for flight; discontinues the flight for unairworthy conditions | 14 CFR 91.3(a), 91.7(b) | No |
| Part 133 certificate holder (the aviation operator) | Size, weight and manner of load connection; unconditional stop authority; holds the certificate, the approved manual and the operating limitations | 29 CFR 1926.551(h); 14 CFR 133.33(a), 133.45, 133.47 | No |
| Chief pilot | Designated to the FAA and acceptable to the Administrator; demonstrates the knowledge and skill standard; may accept that demonstration from other company pilots | 14 CFR 133.21(b), 133.23, 133.37(a)(1) | No |
| Signalperson | Constant reliable communication with the pilot throughout loading and unloading, while remaining distinctly recognizable from the rest of the crew | 29 CFR 1926.551(n), (r) | The role is fixed; the rule does not say whose employee fills it |
| Hookup crew | Engages and disengages slings; works beneath a hovering aircraft only when necessary and by a provided safe means of access; touches the load only after grounding or in rubber gloves | 29 CFR 1926.551(i), (j) | Employer is unstated in the rule, so yes in practice |
| Receiving crew | Complete eye protection and chin-strapped hard hats; no loose clothing; clear of the 100 ft loose-gear radius | 29 CFR 1926.551(e), (f) | Employer is whoever the workers work for |
| General contractor or construction manager | Reasonable care to prevent and detect violations across the site, at a lower standard than for its own employees | OSHA Directive CPL 02-00-124 | No. Status follows authority, contractual or actual |
| Political subdivision (city, county, police) | Excludes unauthorized persons from the operational area for the dates stated in the plan | 14 CFR 133.33(d)(1); AC 133-1B signed letter of agreement | It is itself the transfer |
| Property or building owner | Vacating occupied buildings under the route, disclosing structure, granting access | No federal rule assigns it; the congested area plan form demands the information | Contract only |
| Load owner, fabricator or engineer of record | Certified weight, centre of gravity, rated pick points, and the structural capacity of what receives the load | No federal aviation or OSHA rule assigns it | Contract only |
Roles are listed in descending order of how firmly federal law pins them. The bottom four rows are the ones that generate disputes, because the duty is real, the consequence of failure is immediate, and no regulation names the party who owes it.
The multi-employer overlay decides who gets the citation
OSHA does not resolve the "whose employee" question inside 1926.551. It resolves it site-wide through Directive CPL 02-00-124, effective 10 December 1999, which sorts every employer on a multi-employer worksite into four categories. The creating employer is "the employer that caused a hazardous condition that violates an OSHA standard." The exposing employer is "an employer whose own employees are exposed to the hazard." The correcting employer is one "engaged in a common undertaking, on the same worksite, as the exposing employer" and "responsible for correcting a hazard." The controlling employer is "an employer who has general supervisory authority over the worksite, including the power to correct safety and health violations itself or require others to correct them."
The clause that matters most to a general contractor follows immediately: "Control can be established by contract or, in the absence of explicit contractual provisions, by the exercise of control in practice." A subcontract that assigns every aviation-adjacent safety obligation to the operator does not end the analysis. If the general contractor runs the site, it is a controlling employer regardless of what the flow-down says, and the directive is explicit that an employer may hold more than one of the four roles at once.
What the directive asks of a controlling employer is calibrated, not absolute. It must exercise reasonable care to prevent and detect violations, and OSHA states plainly that "the controlling employer is not normally required to inspect for hazards as frequently or to have the same level of knowledge of the applicable standards or of trade expertise as the employer it has hired." The listed factors include the scale and complexity of the site, the nature of the trade, and how much the controlling employer knows about the safety history and expertise of the firm it engaged. That last factor is the regulatory reason operator vetting is a safety activity and not just a procurement one, and it interacts directly with the certificate and coverage checks described in the AHLH review of lift insurance and liability requirements.
The duties no federal rule assigns
Below the regulatory layer sits a set of obligations that are indispensable to the lift and invisible to the rulebook. Each one has a natural owner. None of them has a citation attached if the contract stays silent, which is precisely why they end up argued about after the fact.
| Obligation | Natural owner | Instrument that fixes it |
|---|---|---|
| Certified weight and centre of gravity of every flyable item | Contractor or fabricator supplying the load | Contract. The regulatory consequence still lands on the operator under 1926.551(h) and the ceiling still sits at the manufacturer's rating under 1926.551(k) |
| Engineered and rated pick points on the load | Load designer or fabricator | The load's own engineering and the ASME B30 rigging series |
| Structural capacity of the receiving curb, roof or foundation | Owner's engineer of record | Building code, not an aviation rule |
| Exclusion of the public outside a congested area | General contractor or site owner | Contract. There is no letter-of-agreement mechanism outside 14 CFR 133.33(d) |
| Site access, staging area, fuel truck route and landing zone | General contractor | Contract |
| Weather and no-go decision | Pilot in command, inside the operator's own minimums | 14 CFR 91.3(a) for the decision; the contract for what the day costs |
| Standby time, weather days and re-mobilization | Whichever party the agreement names | Contract only |
| Additional insured status, waiver of subrogation, on-hook cargo limits | Contractor's risk manager and the operator's broker | Contract and the certificate of insurance |
The first row is the one that turns into litigation. A load flown at an estimated weight is a contractual failure by the party that estimated it and a regulatory exposure for the operator that accepted it, and those two facts do not cancel out.
Cost allocation follows the same logic. A weather day is a flight-safety decision under 14 CFR 91.3(a) and a money decision under the agreement, and the two are settled by different documents. The comparative economics of that exposure against a ground crane are worked through in the AHLH analysis of helicopter versus crane total cost, and the site-condition inputs that drive it are catalogued in the lift site survey checklist.
The daily briefing is where the assignment actually happens
Four separate duties attach to the hours before the first pick of each day, and together they form the only moment when the whole role structure is stated out loud to the people executing it.
- The briefing itself. 29 CFR 1926.551(b): "Prior to each day's operation a briefing shall be conducted. This briefing shall set forth the plan of operation for the pilot and ground personnel." Each day, not each project and not each week.
- The crew briefing by the pilot in command. 14 CFR 133.35(b) requires the pilot in command to ensure all persons are briefed before takeoff on all pertinent normal, abnormal and emergency procedures and on the equipment to be used.
- The signal system check. 29 CFR 1926.551(n) requires the signal system, radio or hand, to be understood and checked in advance of hoisting the load, which is where the designation of the signalperson becomes concrete.
- The hook test. 29 CFR 1926.551(d) requires electrically operated cargo hooks to be tested prior to each day's operation to confirm the release functions both electrically and mechanically.
OSHA 1926.551 Ground crew rule 14 CFR 133 External load certificate
Nothing in the standard requires that briefing to be written, which is a gap worth closing voluntarily. A signed daily briefing sheet naming the signalperson, the hookup crew, the frequency in use, the fall zone, the abort call and the person authorized to stop work converts an oral understanding into the document that answers the question this article opens with. It is also the only record likely to exist after an incident, and the roles it names are the ones that will be read back. The rigging side of that same record is covered in the AHLH guide to rigging a helicopter lift, and the regulatory frame around the whole certificate sits on the external load operations reference.
The shape of the answer, then, is narrower than the question suggests. Federal law fixes the aircraft, the connection of the load and the decision to fly to the aviation operator and its pilot in command, and it fixes them so firmly that no agreement can move them. It fixes the pad and the people on it to whichever employer created, is exposed to, can correct or controls the hazard, and it decides which of those applies from the facts rather than from the paperwork. About everything in between, from the certified weight to the standby rate, it says nothing at all. That silence is not an oversight in the rules. It is the part of the job the contract is written to do, and a lift that goes wrong usually went wrong there first.
